The nice thing about a paladin tank is that they build threat off getting hit, as opposed to my warrior which must be proactive to build threat. If you just put up righteous fury, blessing of sanctuary, and retribution aura, you can usually just stand there and be fine. Add consecration in and your golden. IMO, this is why a paladin makes such a great multibox tank.

As for the button thing, I have some overlap on my buttons, but it is a non-issue because of how they overlap. For example, my lightning bolt spell is also a seal. However, since I'm targeting an enemy, the seal doesn't really do anything (except cause the glowing hand, which I just click 2 again to get rid of). I also mouse click my judgments, but that's really just because I've been too lazy to figure out something better.